package module.decode.p25;
import java.util.BitSet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import bits.BinaryMessage;
/**
* Utility class to process interleave of P25 Voice and Data messages.
*/
public class P25Interleave
{
private final static Logger mLog =
LoggerFactory.getLogger( P25Interleave.class );
private static int[] DATA_INTERLEAVE = new int[] { 0,1,2,3,52,53,54,55,100,
101,102,103,148,149,150,151,4,5,6,7,56,57,58,59,104,105,106,107,152,153,
154,155,8,9,10,11,60,61,62,63,108,109,110,111,156,157,158,159,12,13,14,
15,64,65,66,67,112,113,114,115,160,161,162,163,16,17,18,19,68,69,70,71,
116,117,118,119,164,165,166,167,20,21,22,23,72,73,74,75,120,121,122,123,
168,169,170,171,24,25,26,27,76,77,78,79,124,125,126,127,172,173,174,175,
28,29,30,31,80,81,82,83,128,129,130,131,176,177,178,179,32,33,34,35,84,
85,86,87,132,133,134,135,180,181,182,183,36,37,38,39,88,89,90,91,136,
137,138,139,184,185,186,187,40,41,42,43,92,93,94,95,140,141,142,143,188,
189,190,191,44,45,46,47,96,97,98,99,144,145,146,147,192,193,194,195,48,
49,50,51 };
private static int[] DATA_DEINTERLEAVE = new int[] { 0,1,2,3,16,17,18,19,32,
33,34,35,48,49,50,51,64,65,66,67,80,81,82,83,96,97,98,99,112,113,114,115,
128,129,130,131,144,145,146,147,160,161,162,163,176,177,178,179,192,193,
194,195,4,5,6,7,20,21,22,23,36,37,38,39,52,53,54,55,68,69,70,71,84,85,
86,87,100,101,102,103,116,117,118,119,132,133,134,135,148,149,150,151,
164,165,166,167,180,181,182,183,8,9,10,11,24,25,26,27,40,41,42,43,56,57,
58,59,72,73,74,75,88,89,90,91,104,105,106,107,120,121,122,123,136,137,
138,139,152,153,154,155,168,169,170,171,184,185,186,187,12,13,14,15,28,
29,30,31,44,45,46,47,60,61,62,63,76,77,78,79,92,93,94,95,108,109,110,
111,124,125,126,127,140,141,142,143,156,157,158,159,172,173,174,175,188,
189,190,191 };
private static int[] VOICE_INTERLEAVE = new int[] { 0,24,48,72,96,120,25,
1,73,49,121,97,2,26,50,74,98,122,27,3,75,51,123,99,4,28,52,76,100,124,
29,5,77,53,125,101,6,30,54,78,102,126,31,7,79,55,127,103,8,32,56,80,104,
128,33,9,81,57,129,105,10,34,58,82,106,130,35,11,83,59,131,107,12,36,60,
84,108,132,37,13,85,61,133,109,14,38,62,86,110,134,39,87,15,63,135,111,
16,40,64,88,112,136,41,17,89,65,137,113,18,42,66,90,114,138,43,19,91,
67,139,115,20,44,68,92,116,140,45,21,93,69,141,117,22,46,70,94,119,142,
47,23,95,71,143,118 };
private static int[] VOICE_DEINTERLEAVE = new int[] { 0,7,12,19,24,31,36,43,
48,55,60,67,72,79,84,91,96,103,108,115,120,127,132,139,1,6,13,18,25,30,
37,42,49,54,61,66,73,78,85,90,97,102,109,114,121,126,133,138,2,9,14,21,
26,33,38,45,50,57,62,69,74,81,86,93,98,105,110,117,122,129,134,141,3,8,
15,20,27,32,39,44,51,56,63,68,75,80,87,92,99,104,111,116,123,128,135,
140,4,11,16,23,28,35,40,47,52,59,64,71,76,83,88,95,100,107,112,119,124,
131,136,143,5,10,17,22,29,34,41,46,53,58,65,70,77,82,89,94,101,106,113,
118,125,130,137,142 };
/**
* Deinterleaves the 196-bit block in message, identified by start and end
* bit positions. Note: end index (exclusive) should be one more than the
* last bit in the block.
*
* @param message - source message to deinterleave
* @param start - starting bit index for the block
* @param end - ending bit index for the block, plus 1
*/
public static BinaryMessage deinterleaveData( BinaryMessage message,
int start, int end )
{
return deinterleave( DATA_DEINTERLEAVE, message, start, end );
}
public static BinaryMessage deinterleaveVoice( BinaryMessage message,
int start, int end )
{
return deinterleave( VOICE_DEINTERLEAVE, message, start, end );
}
public static BinaryMessage deinterleave( int[] pattern, BinaryMessage message,
int start, int end )
{
BitSet original = message.get( start, end );
/* Clear block bits in source message */
message.clear( start, end );
/* Iterate only the set bits in the original message and apply
* the deinterleave -- we don't have to evaluate the 0 bits */
for (int i = original.nextSetBit( 0 );
i >= 0 && i < pattern.length;
i = original.nextSetBit( i + 1 ) )
{
message.set( start + pattern[ i ] );
}
return message;
}
/**
* Interleaves the 196-bit block in message, identified by start and end
* bit positions. Note: end index (exclusive) should be one more than the
* last bit in the block.
*
* @param message - source message to interleave
* @param start - starting bit index for the block
* @param end - ending bit index for the block, plus 1
*/
public static BinaryMessage interleaveData( BinaryMessage message,
int start, int end )
{
return interleave( DATA_INTERLEAVE, message, start, end );
}
public static BinaryMessage interleaveVoice( BinaryMessage message,
int start, int end )
{
return interleave( VOICE_INTERLEAVE, message, start, end );
}
public static BinaryMessage interleave( int[] pattern, BinaryMessage message,
int start, int end )
{
BitSet original = message.get( start, end );
/* Clear block bits in source message */
message.clear( start, end );
/* Iterate only the set bits in the original message and apply
* the deinterleave -- we don't have to evaluate the 0 bits */
for (int i = original.nextSetBit( 0 );
i >= 0 && i < pattern.length;
i = original.nextSetBit( i + 1 ) )
{
message.set( start + pattern[ i ] );
}
return message;
}
}